It is an honor to see Daniel Ellsberg's copy of the Pentagon Papers. It has many of his notes in it, often trying to figure out the kill estimates.
I am reading his autobiography "Secrets", available to be borrowed from openlibrary.org
, and it is very good.
The movie "The Most Dangerous Man in America" is fantastic, and is a good biography of Dr. Ellsberg and the impact of the Pentagon Papers on history.